In the case of textile machines such as spinning machines or winders, in which a thread is continuously produced or delivered by a delivery bobbin and is wound onto a bobbin, the thread must be re-pieced after interruptions of the production process, such as in the case of a thread break or a clearer cut. For this purpose, it has become known to search for the end of the thread traveling on the bobbin with the aid of a suction nozzle, and to suction the end of the thread into the suction nozzle in order to transfer the end from there to further handling units for piecing.
DE 3 515 765 A1 describes a suction nozzle which is situated in a displaceable maintenance unit. After the thread has been successfully suctioned in, the suction nozzle is removed slightly away from the bobbin surface, and so the suctioned-in thread is tensioned between the suction nozzle and the bobbin. Thereafter, a feeder unit, which is also situated in the displaceable maintenance unit, is moved toward the thread. The feeder unit grasps the tensioned thread and, while forming a thread loop, transfers the thread to a further handling unit for piecing.
In addition, textile machines have become known, in which each of the workstations includes an associated suction nozzle. A textile machine of this type is described in EP 1 283 288 A2. In this case, provided at each of the workstations is a pivotably mounted suction nozzle which, in a first position, picks up the thread from the bobbin surface and, after the thread end has been successfully suctioned in, is swiveled into a second position in order to deliver the suctioned-in thread end to further handling units of the workstation. The pivotable suction nozzle requires a comparatively large amount of space and has a complex design.
Moreover, DE 10 2015 112 660 A1 describes a textile machine comprising an associated suction nozzle at each workstation, which is fixedly situated at the workstation. A movable feeder unit is assigned to the fixed suction nozzle in order to nevertheless enable the thread end to be delivered to a further handling unit of the workstation. The feeder unit includes a thread guide area which is introduced into a suction duct of the suction nozzle before the thread end is suctioned in, and so the thread end simultaneously enters the thread guide area of the feeder unit when suctioned into the suction nozzle. After the thread end has been successfully picked up, the feeder unit can be swiveled in order to deliver the thread end to the further handling unit while forming a thread loop. The suction nozzle includes an entry opening for the thread guide area of the feeder unit and for guiding the suctioned-in thread out of the suction nozzle. This entry opening must be sealed during the search for the thread end on the bobbin surface. The feeder unit comprises a cover element for this purpose.